Six things I really like about new vegas so far.
1. Stealth mechanics is greatly improved. I took out the entire outside field of the NCR correctional facility with just a vermit rifle + scope on the large hill. Then I went down, put on some powder ganger armor, went inside the buildings and slowly took them out one by one.
2. There is more unique voices, I haven't heard the same voice twice unlike in Fallout 3 where every old man has the same voice, every raider has the same voice, every black guy has the same voice, etc.
3. Hardcore mode, it really makes the game a little more fun and challenging for me. For the first time I ran away from a giant scorpion and it's not just one giant scorpion it's usually 2 or 3 at the same time. I've never ran away from anything in Fallout 3, not even death claws.
4. New Vegas captures the true style of Fallout 1 and 2. No surprise there because the original creators were working on New Vegas.
5. I love ironsights, I took off my crosshair because of it so I have the realism intact. I can get pretty good at shooting with no crosshair sometimes I don't even need to use ironsights.
6. Basically the whole game is like Obsidian saying: We are fixing what bethesda forgeted up with their Fallout 3 game, we are making a true fallout game.